France is the first to follow the United States’ lead bombing the self-proclaimed jihadist Islamic State (IS). French Air Force Dassault Rafale multi-role fighters struck in Iraq on Friday, near Mosul.

Hollande said: “Other actions are expected in the coming days with the same goal to weaken this terrorist organisation, and help the Iraqi authorities. By that I mean Iraqi troops and Kurdish Peshmerga based in Iraq.”

The Islamic State on Monday called for attacks in France and against French citizens everywhere. France is on heightened anti-terrorism alert, with more soldiers than usual on guard at busy public sites.

Militants who fought with rebel groups in Syria and Iraq have returned to France, requiring surveillance and other extra security.

French Foreign Minister Laurent Fabius personally welcomed some 150 mostly Christian refugees flown on board a French government plane to France from Iraqi Kurdistan on Saturday, a few of the many threatened by Islamic State.

“We are defending ourselves; it’s not only generosity,” Fabius said. “There are quite a few French people who are leaving to wage jihad. We need to be extremely active and vigilant to prevent them from coming back and doing things in France.”

Attackers acting alone are considered a serious threat elsewhere in Europe also, in the way that, in May, Mehdi Nemmouche, a French national of Algerian origin opened fire at the Jewish Museum of Belgium in Brussels, killing four people. The gunman is also suspected of torturing captives while in Syria. He was arrested in Marseille and extradited to Belgium.

In 2012, a French national of Algerian origin, Mohamed Merah fatally shot three French soldiers, three Jewish children and a rabbi in the cities of Montauban and Toulouse, wounding others. Police finally trapped and killed him. He had been to Afghanistan and Pakistan and, it’s thought, Syria.

On Tuesday, three suspected jihadists returning from Syria were allowed to walk free unquestioned by French airport police after Turkish authorities had arrested and put them on a plane to Marseilles. One of them was a brother-in-law of Merah. Another carries a previous terrorism-related conviction. Afterwards, the three turned themselves in.